Old Boat, old toilets.....

[OLD HOUSEBOATER]

Most camper chemicals are "Odor Masks" that work on small tanks that are frequently dumped. Many/most actually kill the good bacteria that is needed to prevent the sulfide gasses from being formed.

Odorlos is a nitrate containing product that promotes bacterial action in the tank to mitigate and reduce the sulfide gasses.

Below is a wordy article that you might be interested in.

http://www.rvlifestyleexperts.com/fu...AND_BEYOND.pdf

Suggest you give your tank the best cleaning it ever had and start fresh with KO or Oderlos.

Come back in a month and tell us your results. Can I suggest a bigger tank or more frequent pump outs.

Another thing to look at is the amount of flush water you use with each flush. Is there a way to regulate it?

[easttnboater]

Most of my system is plumbed in hard PVC. The little bit of the vent that is flex pipe is the white pipe that you described. I wrapped mine in aluminum foil to offset any permeation.

One other question - rather personal - do you and your guests use the toilet for both bodily functions? If there is no number two in your system, then it will always smell.

[GoVols]

We let our toilets have it with both barrels! LOL!

I'm going to need to look at my system to see if I can replace the hose inside my wall. I can access ~ 1' of it inside the wall as it comes up from under the the boat, through the floor, and travels on up the interior of the wall toward the top of the boat. Under the boat, I have access to the entire length before it goes through the floor. Outside, there's a simple round vent opening, but I don't think I can pull the vent off to access the hose barb / fitting on the other end.

Maybe I can run a new vent hose somewhere else?

[OLD HOUSEBOATER]

Running a new hose isn't going to help if you flood it. Is your current vent connection as high on the tank as possible?

[easttnboater]

Does the vent line come up inside a cabinet? If you drilled a hole from the outside through the vent opening, would it come out inside a cabinet?

[easttnboater]

FYI - the purchased canister filters use a piece of foam at each end to keep the charcoal inside the canister. You could use anything that you can easily blow through - foam, coffee filter, ....

[GoVols]

Ok, so I spent some time carefully taking apart the wall in the guest cabin in order to access the permiated vent hose. It didn't take me long to expose the hose and determine I'm working with a 3/4" ID hose. Next, I went to Home Depot where I spent ~30 minutes combing the pipe isle to gather the stuff needed to build myself a refillable carbon canister out of PVC pipe. $50 and an hour later my solution is complete. I'm replacing the complete run of the worn-out hose inside the cabin wall with 3/4" ID high density PVC pipe. I'm splicing in a foot-long 2" ID PVC "chamber" I built that'll contain a whole bunch of aquarium filter carbon pellets I bought at walmart. To keep the carbon in the chamber, I'm simply stuffing the aquarium filter media in the bottom 1st, pouring the carbon on top, and placing another piece of filter media ontop. 1 end of the chamber can be removed, which makes it refillable / reuseable. I'm tying in both ends of this complete contraption to the existing system using 3/4" hose barbs. There will only be maybe 6" of hose on top connecting to the external vent and maybe 6" at the bottom where the hose comes from underneath the boat. So, I'm replacing about 7' of this permiated hose altogether, which should definitely keep the stink out of the cabin from now on. I plan to finish installation tonight or this weekend. If everything works correctly, I should be stink-free when flushing -- I HOPE!

Under the boat (between the pontoons), I still have 2 - 1.5" spa hoses running from my 2 toilets to the holding tank as well as ~7' of the 3/4" vent hose. I may get brave and replace all of them with PVC as well, but that would be more difficult, since I'd be swimming in the water while working on everything. Maybe I'll just beach the boat and do it there instead. Fun stuff!

[easttnboater]

Sounds like you have it well in hand. I would replace as much as possible with PVC. It is a one time effort that will last forever.

[GoVols]

Completed my project Friday evening. I have pictures, but this site won't allow me to post them. I've tried every which way to resize and rename the pictures, but it still doesn't work.

At any rate, the odor we've put up with for the last 4 years magically disappeared the moment I completed this project. It was always a little musty in the guest cabin and I'd clear the dock any time the toilet was flushed. I have no idea why this wasn't built this way to begin with. I sent my suggestions and pictures to my boat's manufacturer as well. Hopefully he's changed his system design / construction since my boat was built 9 years ago.